Half a batch of Short Crust (Pâte Brisée)
5 – 6 medium cooking apples (varieties like Granny Smith, Honeycrisp, or Braeburn)
1/4 Cup granulated sugar
1 Tbsp fruity traditional or white balsamic vinegar (flavors like Blackberry Ginger or Cara-Cara Orange Vanilla are great)
2 Tbsp water
1 Tbsp Demerara Sugar
Roll out dough between sheets of parchment paper to form an 1/8-inch-thick round, 14 inches in diameter. Remove top sheet of parchment. Using the bottom parchment sheet as an aid, transfer thinly-rolled dough from the parchment to a large unrimmed baking sheet. Chill in refrigerator for 15 minutes.
Meanwhile, preheat oven to 450°F.
Whisk the single egg with 2 Tbsp water to make an egg wash. Peel, core and slice apples into 1/8 inch slices. Toss the apple slices, granulated sugar and vinegar together in a bowl, coating thoroughly. Pour sugared apples into the center of the dough and spread them out, leaving a 2 inch border. Gently fold the edges of the pie crust over the sugared apples, pinching together any cracks that form in the dough, leaving an uneven, “rustic” opening at the top. Brush the top edges of the crust with the egg wash, and sprinkle top evenly with the Demerara Sugar.
Bake galette for 20 minutes. Then reduce oven temperature to 375° and continue baking, until galette is golden brown, about 30 minutes more.
Remove sheet from oven and allow galette to cool at least 20 minutes before transferring to a serving platter.